This invention relates to seals for passages between the cylinder block and the cylinder head for internal combustion engines. The new seal enhances the use of copper head gaskets with deformable bead seals for sealing between cylinder blocks and cylinder heads.
Automobile engines have been modified to produce engine combustion pressures that cause blown head gaskets when using the standard composite or sandwich type cylinder head gaskets. One solution to this problem for high performance engines has been the use of annealed sheet copper for the head gasket material. The copper material conducts heat and can tolerate higher temperatures. It also has high tensile strength, good elasticity and malleability for use in sealing surfaces. The use of a copper head gasket normally includes use of a wire O-ring inserted in a groove cut in the engine block around the cylinder bore.
While copper head gaskets have been shown to be effective for combustion sealing, they may be prone to leak coolant and oil. Currently a sealant may be applied to both sides of the head gasket from either a tube or spray can. However, use of applied sealants has not been found to be effective for sealing fluid passages.
There is a need for an effective seal for combustion pressure around the cylinder bore as well as sealing of passages through which liquids such as coolant and oil pass. In use of copper head gaskets it may be important that the head gasket be structured for ease of installation as improper application of sealants may produce a poor seal.